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Resonance with toothed drive belts

Resonance with toothed drive belts

Resonance with toothed drive belts

We have an acute noise problem caused by resonance of a small toothed drive system Polyurethane belt driving 0.5 KW via a 50 mm pulley to a 180 mm pulley It is a standard belt and "cogged pulley" rather than a zero backlash.cre
Any comments much appreciated

RE: Resonance with toothed drive belts

There are several slightly different profiles in use for belt teeth and for pulley teeth.
None are really compatible.
All are easy to misidentify.
I.e., there ain't no 'standard'.

Double check that you ordered the proper parts,
and that you got exactly what you ordered.

Is this a new installation, or a replacement of something that worked before?

Mike Halloran
Pembroke Pines, FL, USA

RE: Resonance with toothed drive belts

I came across a belt noise problem that ended up being the motor drive frequency.

The system consists of more than these 3 parts, so there is no way to isolate a problem to them.

Perhaps a photo or video would be useful.

RE: Resonance with toothed drive belts

Do you have a torsional or lateral drive resonance? What is the frequency of the sound; tooth mesh? Are the two pulleys in good condition and matched to the belt? Do you have precise angular and offset pulley alignment? Do you have the correct belt tension? Can you change speed to determine if the sound level changes? There are several noise control measures that might be useful, but additional information about the problem would be necessary.


RE: Resonance with toothed drive belts


Is the belt itself resonating, or is it functioning as a torsion spring element?

Can you replaced your current drive with a heavier duty belt? You probably selected for torque and power. You want something stiffer.

I am aware of two types of fairly standard belts. There is a metric standard which uses rounded teeth, and an English standard which uses flattish, straight tapered teeth. I have not used these lately. I recall that the metric ones have a higher speed rating and than the English ones are stiffer. I believe the English ones are used extensively to drive engine camshafts. Stiffness generally is good when you have vibration problems.


RE: Resonance with toothed drive belts

What are the number of teeth on the fast sprocket, and its rpm?
Is the machine variable speed?

Please don't post any pictures or drawings of your device.

It is possible the tooth mesh frequency is exciting some mechanical resonance, but Toothed belt drives are effective sirens , squishing out pulses of air as each tooth engages the pulley/sprocket. Tricks with chevron V grooves and pressure relief grooves at the bottom of the teeth offer very limited improvement.

If the tooth mesh frequency is up in the audible range then everybody will hear about it, and the situation goes down hill from there.

A spectrum made using a microphone will likely look like the upper image here -

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